Indeed, his premise is quite flawed. Yes, you will have difficulty understanding everything you read at an early stage, but you aren't supposed to be able to understand everything. You read to heavily reinforce the most common words and patterns that show up constantly, and from that base you pick up bits and pieces as you go along.
Under normal circumstances, even if you grind out "knowing" all the words in advance you will still struggle to read any basic sentence and you've essentially wasted time because it's an unskippable step; to be good at reading you need to read a lot. He seems to already know Chinese though, so this might work for him since he is not really having to learn the language or specific vocabulary, just how it's actually written.
Under normal circumstances, even if you grind out "knowing" all the words in advance you will still struggle to read any basic sentence and you've essentially wasted time because it's an unskippable step; to be good at reading you need to read a lot. He seems to already know Chinese though, so this might work for him since he is not really having to learn the language or specific vocabulary, just how it's actually written.